LYMPHATIC SYSTEM Flashcards
(14 cards)
LYMPHATIC SYSTEM
The lymphatic:
> Lymph fluid
> Lymph vessels
> Lymph nodes
> Lymph organs and glands
FUNCTION OF THE LYMPHATIC SYSTEM
- body cells bathed in interstitial fluid
- fliud is from capiliares
- absorbed into the venous ends of capillaries
- drained tissue space by lymphatic capilliares (thin walls) stops tissues from swelling
- lymph fllited through lymph nodes contianing immune cells returned into the bloodstream
LYMPH AND TISSUE FLIUDS
- Excess fluid that comes from the body’s tissues drains into small lymph vessels
- Blood flows from the arterioles into the capillary.
- The pressure of the blood pushes fluid, nutrients and oxygen out of the blood into the fluid that surrounds the cells. This is called tissue fluid or interstitial fluid.
- The cells then use the nutrients for cell metabolism.
The fluid flows back into the blood stream into the subclavian vein.
FUNCTIONS OF THE IMMUNE SYSTEM
Tissue drainage
Absorption in the GI tract: The breakdown products of fat and fat-soluble materials are absorbed into the lymphatic vessels of the villi in the small intestine
BODY COMPONENTS
WHAT ARE LYMPHATIC VESSELS
- Lymph vessels are a network of tubes that
- connect to groups of lymph nodes
throughout the body. - Lymph vessels can be superficial or deep
- They are vessels and capillaries
- The fluid travels through the lymph vessels
and drains into the bloodstream
(subclavian vein)
WHAT ARE LYMPH NODES
- Lymph nodes are found throughout the body, but mainly in the neck, axillae, groin and abdomen.
- They filter and break down bacteria or other harmful cells from the lymph fluid.
- Lymph nodes vary in size.
- Some are as small as a pinhead and others are about the size of a baked bean.
LYMPH NODES IN THE NECK & AXILLA
FUNCTIONS OF LYMPH NODES
- Lymph flows through lymph nodes where it is cleaned by the reticular and lymphatic tissue.
- Organic matter is destroyed by macrophages
- Some lymphocytes complete their maturation in lymph nodes.
- T and B cells multiply here. Antibodies enter the lymph and blood, draining the node
TONSILS
They are collections of lymphoid tissue
They intercept any swallowed or inhaled antigens.
Pharyngeal tonsil
A single tonsil at the back of the nasal cavity
Palatine tonsils
Paired tonsils on the pharyngeal wall at the back of the mouth
Lingual tonsils
At the back and sides of the tongue
SPLEEN
The spleen is the largest lymph organ and it contains reticular and lymphoid tissue.
The cells in the splenic pulp are lymphocytes and macrophages.
The lymph vessels are efferent – they flow out of the spleen
Sinsusoids carry blood within the spleen. They remove ageing or damaged cells from the blood stream.
FUNCTION OF THE SPLEEN
Phagocytosis – old and abnormal erythrocytes and their breakdown products, bilirubin and iron, which are taken to the liver. Leukocytes, platelets and bacteria are also phagocytose
Storage of blood – 350 mls in red pullp.
Immune response – white pulp contains T and B lymphocytes
Erythropoiesis – foetal blood cell production. Can also happen in adults in emergencies.
THYMUS GLAND
It is behind the sternum. It grows in size until puberty, then starts to atrophy.
It consists of 2 lobes joined by areolar tissue. The lobes are divided into lobules, which contain epithelial cells and lymphocytes.
It produces mature T cells, which leave the thymus and enter the blood to other lymphoid tissue or the bloodstream.
MUCOSA-ASSOCIATED LYMPHOID TISSUE - MALT
- Peyer’s patches are large collections of lymphoid tissue in the small intestine.
